Oil circuit breaker



y 22, 1934- G. R. LANGLEY 60,057

OIL CIRCUIT BREAKER Filed Sept. 29, 1951 Inventom Gov don R. Lar le 1 His Attorney.

Patented May 22, 1934 UNITED STATES 1,960,05'i PATENT OFFICE 01L CIRCUIT BREAKER Gordon R; Langley, PeterbormOntario, Canada, assignor to General Electric Company, a corporation of New York Application September 29, 1931, Serial No. 565,816 In Canada October 15, 1930 3 Claims. .(Cl. 200-150) aforesaid type it has heretofore been the practice in a well known type of breaker, for example, to mount the conducting studs and associated fixed contacts, and the operating mechanism for the movable contacts on a cast or fabricated dome member through which the conductor stud bushings and an element of the operating mechanism extend. The oil tank is then releasably secured 15 to the lower part of the mechanism cover surrounding the contacts and operating mechanism. By reason of the shape of the cover or dome member in the above-described structure, assembly of the various pieces of apparatus in their proper positions has presented considerable difficulty, involving increased manufacturing cost and loss of time.

In accordance with my invention the above difficulties are avoided by an improved method of 5 construction wherein the various elements are assembled in proper relation on a flat plate, to

form a sub-assembly, both sides of which are easily accessible, and tothe opposite sides of which may be attached, respectively, an arched or dome cover member, and a suitable receptacle, as the .usual oil tank. This construction is equally applicable to single pole or multiple pole or polyphase circuit breaker construction. In polyphase circuit breaker construction the aforesaid plate may be common to a number of switch casings,

the respective operating mechanisms, switch contacts, dome and tank members all being mounted on said plate.

A principal object of my invention is the provision of an improved oil circuit breaker and method of constructing the same.

My invention will be more fully set forth in the following description referring to the accompanying drawing, and the features of novcity which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Referring to the drawing, Fig. l is a perspective View of a polyphase oil circuit breaker unit constructed in accordance with my invention; Fig. 2 is a detailed plan view of the supporting plate member shown in Fig. 1; Fig. 3 is a fragnientary elevational view corresponding to the section line 3--3 of Fig. 4 and to the section line 33 of Fig. 2, and Fig. l is a fragmentary elevational view taken at right angles to that of Fig. 3 and on the line 4-4 of Fig. 3 likewise corresponding to the section line 4-4 of Fig. 2. 5 Referring to the drawing, there is shown in Fig. 1, by'way of example, a three phase circuit breaker unit including separate switch casings for each phase. The individual switches are simultaneously operated by common operating mechanism which forms no part of the present 55 invention and is not shown in the interest of clearness. The supporting means common to the switches comprises a heavy rolled steel plate 10 which has joined thereto, as by welding, three dome-shaped members 11 suitably formed, as by 'm casting. Each dome member covers the operating mechanism of a single phase circuit breaker, the mechanism having been previously assembled on the plate in a manner hereinafter described.

Projecting through each cover or dome member 11 is a pair of insulated conductor studs 12, and an operating shaft 13 projects through the side of each member 11 for actuating the enclosed mechanism. As above indicated a main operating mechanism may be connected to the shafts 13 3 for operating the same in unison.

The switch casing for each circuit breaker includes an oil tank 14 which is releasably secured. to the lower side of the plate 10, there being a corresponding oil tank for each dome member thereby completing the switch casings. When assembled in operative position the whole unit may be supported by suitable framework 15 on which rests the projecting portions of the plate 10 so that the plate 10 actually supports the polyp-base unit.

In the construction of a three phase circuit breaker unit according to my method, a heavy steel plate of suitable proportions is mounted in a convenient position, preferably horizontally. Suitable openings l6, l8 and 22 for the accommodation of the operating apparatus are then cut therein, conveniently by means of a cutting torch. The bolt holes 1"! are preferably drilled and are so arranged to cooperate with the attaching bolts of the tank members 14-. On one face of the plate are then welded the bearing blocks 19, 20, 21 and 23. The three groups of bearing blocks 19, 20, 21 are for the support of the operating shafts 13 for each of the individual circuit breakers, and the bearing blocks 23, located in. proper relation to the openings 22, are for the support of an element of the operating mechanism for each individual circuit breaker.

When this step in the method has been completed, the steel plate may be reversed or placed in a position where the opposite side is accessible in order to mount additional elements on its second face. A pair of reinforcing straps 24 (Fig. l) are now welded to this face of the plate, one adjacent each edge extending in the longitudinal direction of the plate. The bearing blocks 25 and the U -shaped brackets 26 may now be welded to this face of the plate in their proper relation to the opening 16. Bearing blocks 25 are for the support of an element of the operating mechanism for each individual circuit breaker, and brackets 26 are for the support of a suitable rebound preventing dashpot mechanism 34 (see Fig. 3) one for each of the operating mechanisms. Circular slots 27 (shown in dotted lines in Fig. 2) are now machined in this face of the plate and are arranged to receive the upper end of the tank members 14 in the completed structure.

This completes the preparation of the steel plate, and the elements of the operating mechanism may now be mounted on the bearing blocks. The operating mechanism for the individual cir cult breakers each consists of an operating shaft 13 Journaled in the bearings 19, 20 and 21, and having keyed thereto between the bearings 20 and 21 a lever 29. The lever 29 in turn is connected through a series oi links and levers Jou-r naled in the bearing blocks 23 and 25 at the points 30 and 31 respectively and passing through the openings 22 and 16, to a pivotal point 32 on the operating rod 28. I1 the individual circuit breakers are to be operated in unison the operating shaft 13 may have keyed to it between the bearings 19 and 20 a lever arm 41 (see Fig. 4) which passes through the opening 18, and these lever arms may be connected together by a rod 42. The dashpot mechanisms are mounted in their brackets 26 in the proper position to cushion the impact oi the operating mechanism as it reaches its extreme position. The operating rod 28 located centrally of the plate aperture 16 bears at its upper end on an opening spring assembly 33, and at its lower end (not shown) the movable contacts of the circuit breaker are mounted.

The next step in the method is to mount the arched or dome cover members 11 and weld them to the plate. Each dome 11 is provided with three openings in the top thereof, and along a diameter thereof (see Fig. 4) The two outer openings are for the accommodation 01 the conductor studs 12, and the central or inner opening accommodates the opening spring assembly 33 for the operating rod 28. A cut-away portion 37 is also provided in the lower edge oi. the domes 11 to receive the bearing block 20. The domes 11 are so placed on the plate 10 that the cut-away por-- tion 37 ilts over the bearing block 20, the central opening registers with the opening spring assembly 33, and the openings for the conductor studs register with the centrally disposed plate apertures 16. The domes 11 are then welded to the plate 10 and the bearing blocks 20 as indicated at 39 in Figs. 3 and 4. The cover members 35 for the opening spring assembly 33 are then placed in position in the central openings of the domes 11 and are welded thereto. The conductor studs 12 are next mounted in the domes 11, extending through the outer openings in the top of the domes 11, and through the plate apertures 16. The conductor studs 12 consist of a conducting rod suitably insulated by an insulating cylinder to which is attached the clamping flange 40. At their lower ends (not shown) the conductor studs 12 are provided with suitable means for attaching the fixed contacts, which may be placed in position after the studs 12 have been attached to the domes 11. The conductor studs 12 may be attached to the domes 11 either removably as by bolting or permanently as by welding the flanges 40 to a suitable arrangement in the top or the domes.

When the dome assembly is complete and the fixed and movable contacts have been attached to the conductor studs 12 and the operating rod 28 respectively, the breaker is completed by locating the tanks 14 with their upper edges received in the slots 27. The tanks are provided with threaded studs which pass through the holes 17 of the plate 10 and are suitably retained in position by nuts 17'. Suitable packings are provided in the bottom of the slots 27.

In the structure I have illustrated I have shown three circuit breakers with their operating mechanism mounted on a single plate and a separate dome for each breaker. The completed assembly is readily mounted in position by a supporting framework engaging the projecting portions of the plate 10.

It should be understood that my invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit or my invention.

What I claim as new and desire to secure by Letters Patent oi the United States, is,-

1. An oil circuit breaker including a metal plate provided with a centrally disposed aperture, switch operating mechanism mounted on said plate and positioned in and extending through said aperture, a dome cover member secured to one side of said plate over said mechanism, a pair of insulated conductor studs extending through said aperture at opposite sides of said mechanism and through said dome memher, and an oil tank secured to the opposite side of said plate beneath said dome member completing the switch casing, said plate comprising the supporting means for the casing.

2. An oil circuit breaker of the type including a casing in which relatively movable contacts 115 and an operating mechanism therefor are mounted, comprising a flat metal plate provided with an aperture, said operating mechanism including linkage structure mounted on said plate and positioned in and extending through said aperture, 120 a dome cover member joined to said plate over said operating mechanism, conductor studs ternn'nating at their lower ends in fixed contacts extending through said dome member and the aforesaid aperture, said operating mechanism connected to movable contacts cooperative with said fixed contacts, and an oil filled tank releasably secured to the opposite side of said plate beneath said dome housing said contacts and completing the switch casing.

3. A polyphase circuit breaker unit including a plurality of individual switch casings each having cooperating contacts and an operating mechanism mounted therein, comprising a supporting plate common to said casings, said phase operat- 135 ing mechanisms individually mounted on said plate and positioned in and extending through corresponding apertures therein, a dome cover member for each mechanism joined to said plate over the corresponding aperture, a pair of in- 140 sulated conductor studs mounted in said dome and extending through said aperture and an oil tank secured at the opposite side of said plate beneath each of said dome members housing said contacts and completing the switch casings.

GORDON R. LANGLEY. 

